/Engine/Source/Runtime/UMG/Public/Blueprint/WidgetLayoutLibrary.h
Gets the slot object on the child widget as a Border Slot, allowing you to manipulate layout information.
static [UBorderSlot](API\Runtime\UMG\Components\UBorderSlot) * SlotAsBorderSlot ( [UWidget](API\Runtime\UMG\Components\UWidget) * Widget )